Confusion is more closely linked to going hypo, maybe when he becomes confused encourage him to test his glucose levels ? Best advice for any diabetic on insulin is to be aware of when they go too low, from the outside they may appear pale, disorientated, speech will be affected, possibly sweating/shaking, best treatment is glucose in any form, so can of pop such as coke, apple/orange juice, glucose gel or dextrose tablets or sweets such as jelly babies, not chocolate though as the fat delays the glucose absorption.